send method
Sends an event to the node if the data type matches T. Updates the lastData and adds the event to the stream.
Implementation
void send(EventDTO dto) {
if (dto.data is T) {
var previous = lastData;
var d = EventDTO<T>(dto.data, topic: dto.topic, completer: dto.completer);
lastData = dto.data;
_streamController.add(_NodeEvent<T>(d, previous));
} else {
// an event of a foreign type: it must not be dropped silently, otherwise
// the sender would never get an answer
_completeIfNeeded(dto.completer, null);
}
}